An image forming apparatus, including a laser printer, is known, in which a process cartridge is detachably mounted on a main body casing. The process cartridge is provided with a developing roller, on which toner is carried, and a photosensitive drum which is disposed to face the developing roller and on which an electrostatic latent image is formed.
In such an image forming apparatus, the toner carried on the developing roller is selectively supplied to an electrostatic latent image formed on the photosensitive drum by a developing bias applied to the developing roller, when an image is formed. Then, the electrostatic latent image is developed, and a visible image is formed on the photo sensitive drum. When paper is opposed to the photosensitive drum, the visible image formed on the photosensitive drum is transferred by a transfer roller, so that an image is formed on the paper.
In the main body casing, a contact electrode coming in contact with a roller shaft of the developing roller is provided so as to apply a developing bias to the developing roller.
As such a contact electrode, a contact electrode obtained by the following process is proposed. First, conductive wire is subjected to a bending process such that a bent portion is provided in a portion of the wire. Further, one end thereof is set to a mount section, and the mount section is inserted into a frame of the apparatus. Then, the bent portion is caused to come in point contact with a counterpart electrode (For example, refer to Japanese Patent No. 3116820)